Anal melanoma is a rare and highly aggressive mucosal melanocytic malignancy. It is the third most common after melanomas of the skin and retina. The peak incidence in seen in the sixth and seventh decades. The clinical symptoms are pain, anal mass, bleeding per rectum, tenesmus or change in the bowel habits. It affects anal canal, rectum or both with a tendency to spread along submucosal planes. It is mostly beyond complete resection at the time of diagnosis and majority of patients die of metastasis. MR imaging significantly increases the diagnosis of anal melanoma in its early stages.